In 1949 a team of astronomers discovered a starOpens in a new tab 1,300 light-years from Earth, at the head of Orion the Hunter. Since then, astronomers have found that the star—GW Orionis—has two stellar companions. Now, astronomers using observations from the Atacama Large Millimeter/submillimeter Array (or ALMA) telescope in northern Chile say they’ve detected evidence of a planet orbiting the triple star system, making it the first of its kind. And a potential IRL TatooineOpens in a new tab one-upper.
ESO/Exeter/Kraus et al., ALMA (ESO/NAOJ/NRAO)Opens in a new tab
SYFY WireOpens in a new tab reported on the detection of what may be the first-ever planet—or planets—on record orbiting a triple star system. One that’s a “hierarchical trinary,” as two of the member stars orbit each other closely with the third farther out. The astronomers used observations from ALMA, an assembly of 66 radio telescopes, for their analysis.
In a paper published in the journal Monthly Notices of the Royal Astronomical SocietyOpens in a new tab, the astronomers outlined how they analyzed the dust disc around the triple star system. They applied orbital and particle simulators to ALMA’s observations of both the trinary system itself and the disc with gaps in it.
Prior to this study, astronomers hypothesized the disc’s gaps may be the result of torque from the hierarchy’s outer star. That is, a result of the outer star’s gravity tugging on the discOpens in a new tab, warping and breaking into bands. But the astronomers found that the presence of a massive planet (or planets) is more likely behind the disc’s gaps.
Although astronomers have no direct evidence of the planet(s), the hypothesis seems to coincide with the way planets form generally. In our own solar system, for example, the planets orbiting the SunOpens in a new tab originally formed from a disc of dust surrounding their parent star.
ESO/L. Calçada, Exeter/Kraus et al.
“It’s really exciting because it makes the theory of planet formation really robust,” Jeremy Smallwood, study lead author and recent Ph.D. graduate in astronomy from the University of Nevada, Las Vegas, said in a press releaseOpens in a new tab. “It could mean that planet formation is much more active than we thought, which is pretty cool,” Smallwood added. Indeed, we may have to start considering the possibility not just of IRL Tatooines, but also Batuu systemsOpens in a new tab as well.
